1. Field of the Invention
The embodiments of the invention generally relate to integrated circuit technology, and more particularly to devices and techniques for evaluating operation parameters of integrated circuit chips.
2. Description of the Related Art
In the integrated circuit industry, it is imperative to monitor the operation of an integrated circuit for control, testing, and/or diagnostic purposes. Conventionally, signals are made either internally using electrical readouts (e.g., diagnostic circuits, latches, scan chains, and related structures), or remotely using physical sensors (e.g., charge coupling device (CCD) detectors, thermal imagers, and magnetic field sensors). Unfortunately, electrical readout circuitry generally occupies valuable chip area, induces performance degradation or load to critical circuits on the chip, and cannot specifically pinpoint the location of problems.
Furthermore, remote sensing using physical sensors from the front side of chips is typically blocked by metal wiring and surface interconnects or input/output (I/O) devices. From the back side, signals tend to be severely attenuated by the silicon substrate and blocked by metal wiring as from the front side. Moreover, remote sensors are also generally lacking with regard to spatial resolution, where the best case has shown to be approximately on the order of one micron, which is already ten times greater than the minimum integrated circuit features.
Therefore, there remains a need for a novel structure and method for monitoring the operation of an integrated circuit during operation, which further provides enhanced resolution qualities, is operable at the wafer level or on packaged parts, does not occupy significant chip area, and does not negatively impact circuit and/or device performance.